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Shakeel Butt
1813e51eec
For several years, MEMCG_CHARGE_BATCH was kept at 32 but with bigger machines and the network intensive workloads requiring througput in Gbps, 32 is too small and makes the memcg charging path a bottleneck. For now, increase it to 64 for easy acceptance to 6.0. We will need to revisit this in future for ever increasing demand of higher performance. Please note that the memcg charge path drain the per-cpu memcg charge stock, so there should not be any oom behavior change. Though it does have impact on rstat flushing and high limit reclaim backoff. To evaluate the impact of this optimization, on a 72 CPUs machine, we ran the following workload in a three level of cgroup hierarchy. $ netserver -6 # 36 instances of netperf with following params $ netperf -6 -H ::1 -l 60 -t TCP_SENDFILE -- -m 10K Results (average throughput of netperf): Without (6.0-rc1) 10482.7 Mbps With patch 17064.7 Mbps (62.7% improvement) With the patch, the throughput improved by 62.7%. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Shakeel Butt <[email protected]> Reported-by: kernel test robot <[email protected]> Acked-by: Soheil Hassas Yeganeh <[email protected]> Reviewed-by: Feng Tang <[email protected]> Acked-by: Roman Gushchin <[email protected]> Acked-by: Muchun Song <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: "Michal Koutný" <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.